This invention relates to the apparatus and method for cutting elastomeric material into volumetric samples in such a manner that the elastomeric material has a homogeneous composition without air bubbles and may be reproduced at accurate masses by variable volumetric adjustment.
Heretofore, many attempts have been made to produce apparatus to effectively separate a portion of material from stock with a die cutting or punching mechanism. For example, U.S. Pat. Nos. 120,162; 1,506,480; 1,166,613; 1,755,191; 2,049,624; and 2,369,896 disclose a variety of cutting mechanisms for materials. Should the cutting apparatus employ a punching mechanism, U.S. Pat. Nos. 295,227; 904,714; and 3,465,634 disclose a pointed punch configuration which forms a conical contact with the material being cut prior to the actual cutting edge making contact with a stationary surface. In a different direction, punching mechanisms have taught a curved surface to engage the stationary cutting edge. U.S. Pat. Nos. 3,288,665 and 4,123,956 have disclosed such a feature.
The punching and die cutting mechanisms so disclosed in the art have relied upon the swiftness of mechanism and the sharpness of cutting surface to achieve the desired product. Such reliance has been proved to be misplaced, wherein the control over quality of the cut product with certain materials has proved to be volumetrically inaccurate.
Once the material has been cut or punched, improvements to the basic punch design have been utilized to remove the cut material or slug from the cutting or punching area. U.S. Pat. Nos. 3,296,905 and 3,823,630 have provided means for removing the punched slug from the cutting area. However, these mechanisms do not serve any purpose during the cutting or punching operation.
When elastomeric material, particularly uncured or green rubber or elastomeric materials of a similar resiliency, are placed in a punching mechanism according to the designs described in the art, the material does not achieve a quality cut or punch because of the nature of its inherent resiliency. Particularly, the elastomeric material is unevenly spread under the pressure of the machine prior to the cut. Therefore, the need exists for additional designs and mechanisms for the apparatus to cut or punch elastomeric material to overcome the defects in cutting operations when a resilient material is being manipulated.
Whenever elastomer plugs or samples must be reproducible for precision purposes, the cavity into which the elastomeric material entered prior to cutting must be of a specific and accurate volume. This volumetric requirement is not found in the art, and the reproducibility of volumetric samples for precision purposes is greatly desired.